Abstract: This application is concerned with room temperature vulcanizing compositions useful as mould making materials which are formed by mixing an alpha, omega dihydroxy polysiloxane, a condensation polydimethylsiloxane, catalyst and a crosslinking agent which comprises a tri- or tetra-alkoxy silane or siloxane in which the alkoxy groups contain more than two carbon atoms. Moulds made with these materials on epoxy masters show improved usage; the improvement is related to the size of the alkoxy "leaving group" and the proportion of crosslinker and condensation catalyst.

Abstract: The present invention provides a silicone antifoaming agent composition excellent in the persistence of the foam controlling effect. The silicone antifoaming agent composition comprises a polydiorganosiloxane and silica, which form an antifoaming agent to be improved, and 4 to 2,500 parts by weight per 100 parts by weight of the sum total of the polydiorganosiloxane plus silica of a modified silicone oil having at least one organic group bonded to a silicon atom and having at least one functional group selected from among epoxy, amino, amide, carboxyl, alkoxyl and hydroxyl groups and at least one substituted or unsubstituted polyoxyalkylene group bonded to a silicon atom.

Abstract: The subject-matter of the present invention is to solve the technical problem resulting from the instability in air of polysilanes. For this purpose, it proposes a polysilane-based composition, used particularly for producing silicon carbide, comprising:polysilane chains capable of being degraded by oxidation and the formation of polysiloxane-type products and/or polysilane chains suitable for being bound together directly by a reaction between Si--H and Si--X radicals, and/or indirectly through the intermediary of a crosslinking additive and by a reaction between A--X and A--H radicals, X being an olefin radical, preferably comprising 1 to 18 carbon atoms and, more preferably still, being constituted by a vinyl radical (Vi:--CH.dbd.CH.sub.2), A being an organic, organosilicic or silicic radical;and at least one antioxidant system.

Abstract: An infiltration-type water-based organosilicon composition having excellent performance as a water absorption preventer for construction materials and being stable as an emulsion, which is prepared by emulsifying alkylalkoxysilane and/or its condensate in water in the presence of (a) an anionic emulsifier and/or nonionic emulsifier, (b) a thickener, and (c) an alkaline compound.

Abstract: A conductive polymer comprises a silicon-containing polymer having, in the main chain thereof, Si--Si bonds or both Si--Si bonds and C--C multiple bonds, and ferric chloride doped in said polymer through vapor phase doping. A method for preparing such a conductive polymer is also described.

Abstract: The invention is a composition of matter used in the making of raised characters for use in signs, and a method of manufacturing raised characters made from the composition. The matter is a polymerizable composition comprising a silicone rubber compound, and about 10 to about 50 weight percent of a silica filler based on the weight of the polymerizable composition. Moreover, the composition of matter is a curable composition comprising a vinyl resin selected from a vinyl plastisol or vinyl organosol, and about 10 to about 50 weight percent of a silica filler based on the weight of curable composition. The invention also includes a method of manufacturing raised characters for use in signs comprising machining the characters from a partially cured polymerizable material.

Abstract: An anhydride-functional polymer is obtained by at least partially hydrogenating an unsaturated polymer which was obtained by reacting under ene reaction conditions:(i) an unsaturated anhydride having the structure: ##STR1## wherein R.sub.1 and R.sub.2 are each independently hydrogen, alkyl of 1 to about 6 carbons, or alkoxy of 1 to about 6 carbons, or a halogen; and(ii) at least one polyolefin having at least two carbon-carbon double bonds in the polyolefin backbone and having an average of at least three carbon atoms in the polyolefin backbone between the carbon-carbon double bonds.

Abstract: The silicone rubber composition of the present invention comprises (A) an organopolysiloxane obtained by mixing and heating an organopolysiloxane having a silanol group at both ends of the molecular chain and a silane or a siloxane having two hydrolyzable groups in the molecule, (B) a finely divided silica, and (C) a curing agent. The composition, wherein the content of low-molecule siloxanes is remarkably constrained, is quite useful in the application wherein low-molecular siloxanes are obnoxious, for example, in the application of electrical contacts and parts used adjacent thereto, roll materials of copying machines, gaskets for construction, etc.

Abstract: An anhydride-functional polymer obtained by reacting under graft copolymerization reaction conditions,(A) an unsaturated polymer which was obtained by reacting under ene reaction conditions a mixture of reactants comprising:(i) an unsaturated anhydride having the structure: ##STR1## wherein R.sub.1 and R.sub.2 are each independently hydrogen, alkyl of 1 to about 6 carbons, or alkoxy of 1 to about 6 carbons, or a halogen; and(ii) at least one polyolefin having at least two carbon-carbon double bonds in the polyolefin backbone and having an average of at least three carbon atoms in the polyolefin backbone between the carbon-carbon double bonds; and(B) at least one ethylenically unsaturated monomer which is copolymerizable with the unsaturated polymer.

Abstract: A non-crosslinked endblocked polymer, comprising a preformed aqueous emulsion having a plurality of silanol-terminated polydiorganosiloxane particles, an endcapping silane having the formula R.sub.3 SiX where X is a hydrolyzable group, R is an alkyl group consisting of 1 to 7 carbon atoms, and an organotin catalyst. The composition results in a non-crosslinked polymer, unlike the polymers described in the prior art. It has been found that adding an endblocking silane having only one hydrolyzable group to a preformed polydiorganosiloxane emulsion results in endblocked polydiorganosiloxane molecules free of crosslinks between the polydiorganosiloxane chains.

Abstract: The present invention relates to acetoxy, ketoximo, and alkoxy silicone sealants suitable for use in various sealant applications and additionally food contact applications comprising di-iodomethyl-para-tolylsulfone and having physical properties improved thereby.

Abstract: A silicone gel composition comprising (A) a linear organopolysiloxane having a backbone consisting only of trifluoropropyl-substituted siloxane units and terminated with alkenyl group, (B) an organohydrogenpolysiloxane, (C) a platinum catalyst, and (D) a finely powdered silica whose surfaces have been rendered hydrophobic by treatment with a silicon compound having only methyl groups as substituent groups, such as hexamethyldisilazane, trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, trimethylalkoxysilane, dimethyldialkoxysilane, methyltrialkoxysilane and cyclic or linear dimethylpolysiloxanes. The composition has good thixotropy and can effectively provide a protective layer by spot potting. The silicone gel formed from the composition is excellent in solvent resistance, etc. and is effectively restrained from shrinkage or the like. Therefore the composition is highly suited to use as a protective material for semiconductor-type pressure sensors.

Abstract: A silicone composition is of the addition reaction type which comprises a vinyl group-containing organopolysiloxane, an organohydrogenpolysiloxane which has at least one hydrogen atom joined to a silicon atom in one molecule, a platinum group metal catalyst, and an aluminum oxide powder which is substantially round or spherical in shape with an average particle size of not larger than 50 .mu.m and wherein when the aluminum oxide powder is subjected to extraction of alkali metal ions and halogen ions under conditions of 121.degree. C., 2 atmospheric pressures, 100% R.H. and 20 hours, the contents of both ions are, respectively, not larger than 5 ppm. The cured product obtained from the composition has high thermal conductivity and the composition is useful as a sealant of electric and electronic parts and can prevent the parts from being corroded.

Abstract: A plastic material composed of silicon carbide powder, polycarbosilane, organic solvent, and optionally boron compounds and/or other additives, preferably porosity agents; and the use of this plastic composition for producing shaped parts and semi-finished products by plastic shaping.

Abstract: A heat curable silicone elastomer composition includes (1) an organopolysiloxane having at least two aliphatic unsaturated hydrocarbon groups, (2) an organohydrogenpolysiloxane having at least two hydrogen atoms, and (3) a platinum-containing silicone resin having a melting or softening point of 49.degree. to 150.degree. C. and containing 0.05-0.3 mol % of SiOH group. The composition is storage stable at room temperature and efficiently cures through hydrosilylation reaction at high temperature.

Abstract: Curable compositions including epoxy-functional compounds and polyenes, as well as cyclic polysiloxanes, and/or tetrahedral siloxysilanes, and/or linear polysiloxanes; along with, or instead of these polyenes and silicon compositions, crosslinkable prepolymers prepared from such polyenes and silicon compounds may be included. A curing agent, and yet additionally, a curing accelerator, may also be included. These compositions can be thermally cured, in the presence of hydrosilation catalysts.

Abstract: To a silicone composition comprising (A) an organopolysiloxane having at least two alkenyl groups in a molecule, (B) an organohydrogenpolysiloxane having at least two hydrogen atoms each directly attached to a silicon atom in a molecule, and (C) a platinum catalyst, (D) a compound having a phenyl group and a secondary or tertiary amino group directly attached thereto is added to render the composition flame retardant. The composition cures into a transparent product having improved flame retardancy meeting the UL standard and is suitable for use in the protection of electronic parts like ICs and hybrid ICs.

Abstract: Adhesion-promoting additives for use in curable organosiloxane compositions comprise 1) at least one organosiloxane comprising a) silicon bonded hydrogen atoms and/or ethylenically unsaturated substituents bonded to silicon through carbon and b) at least one silicon atom containing three hydrolyzable groups, and 2) at least one silane containing four alkoxy or enoloxy groups or three of these groups and a hydrocarbon radical containing an epoxy or ethylenically unsaturated group as a substituent.

Abstract: The invention relates to the following novel silanes: methyl vinyl bis-(methyl isobutyl ketoximino) silane; methyl vinyl bis-(methyl amyl ketoximino) silane; methyl tris-(methyl isobutyl ketoximino) silane; vinyl tris-(methyl isobutyl ketoximino) silane; methyl tris-(methyl amyl ketoximino) silane; vinyl tris-(methyl amyl ketoximino) silane; tetrakis-(methyl isobutyl ketoximino) silane; tetrakis-(methyl amyl ketoximino) silane; methoxy tris-(methyl isobutyl ketoximino) silane; ethyl tris-(methyl isobutyl ketoximino) silane; ethoxy tris-(methyl isobutyl ketoximino) silane; methoxy tris-(methyl amyl ketoximino) silane; ethyl tris-(methyl amyl ketoximino) silane; ethoxy tris-(methyl amyl ketoximino) silane; and mixtures thereof.

Abstract: A method for continuously producing a room temperature vulcanizable composition is disclosed. A base mixture of a silanol stopped fluorosilicone polymer, a silica filler and iron oxide are processed in an extruder at an elevated temperature between about 50.degree. and 200.degree. C. Thereafter, a tin based catalyst, an acetoxy cross-linking agent and an optional adhesion promoter are added to the extruder near the exit port. The resulting material has improved storage stability.